US3668126A - Method of producing electrophotographic liquid developers having very fine coloring material - Google Patents

Method of producing electrophotographic liquid developers having very fine coloring material Download PDF

Info

Publication number
US3668126A
US3668126A US699365A US69936568A US3668126A US 3668126 A US3668126 A US 3668126A US 699365 A US699365 A US 699365A US 69936568 A US69936568 A US 69936568A US 3668126 A US3668126 A US 3668126A
Authority
US
United States
Prior art keywords
liquid
carrier liquid
vinyl chloride
oil
charge control
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US699365A
Other languages
English (en)
Inventor
Yasuo Tamai
Satoru Honjo
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujifilm Holdings Corp
Original Assignee
Fuji Photo Film Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP42003908A external-priority patent/JPS5233497B1/ja
Priority to FR1562934D priority Critical patent/FR1562934A/fr
Priority to BE709625A priority patent/BE709625A/fr
Application filed by Fuji Photo Film Co Ltd filed Critical Fuji Photo Film Co Ltd
Priority to US699365A priority patent/US3668126A/en
Priority to GB3319/68A priority patent/GB1218064A/en
Application granted granted Critical
Publication of US3668126A publication Critical patent/US3668126A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/12—Developers with toner particles in liquid developer mixtures
    • G03G9/135—Developers with toner particles in liquid developer mixtures characterised by stabiliser or charge-controlling agents
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/12—Developers with toner particles in liquid developer mixtures
    • G03G9/122—Developers with toner particles in liquid developer mixtures characterised by the colouring agents
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/12—Developers with toner particles in liquid developer mixtures
    • G03G9/125—Developers with toner particles in liquid developer mixtures characterised by the liquid
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/12—Developers with toner particles in liquid developer mixtures
    • G03G9/13—Developers with toner particles in liquid developer mixtures characterised by polymer components
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/12—Developers with toner particles in liquid developer mixtures
    • G03G9/13—Developers with toner particles in liquid developer mixtures characterised by polymer components
    • G03G9/131—Developers with toner particles in liquid developer mixtures characterised by polymer components obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • G03G9/08—Developers with toner particles
    • G03G9/12—Developers with toner particles in liquid developer mixtures
    • G03G9/13—Developers with toner particles in liquid developer mixtures characterised by polymer components
    • G03G9/132—Developers with toner particles in liquid developer mixtures characterised by polymer components obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
    • Y10S430/001—Electric or magnetic imagery, e.g., xerography, electrography, magnetography, etc. Process, composition, or product
    • Y10S430/105—Polymer in developer

Definitions

  • the present invention relates to a liquid developer used for the development of an electrostatic latent image in electrophotography and, in particular, to a liquid developer containing negatively charged toners as well as the process of its preparation.
  • liquid developer consists of fine colloidal particles suspended and dispersed in the electric insulating carrier liquid (for instance, chlorinated hydrocarbon, chlorinatedfluorinated hydrocarbon, aliphatic hydrocarbon, polymethyl siloxane, etc.)
  • the polarity of the colloidal charge is determined by the carrier liquid, substances dissolved in the carrier liquid and the surface condition of the pigment or dye colloid particles to be suspended in the carrier liquid, etc.
  • colloidal particles are covered with suitable insulating resin so as to assure a charge of the desired polarity.
  • pigments or dyestuffs to be suspended and dispersed in carrier liquid for instance, phthalocyanine blue, crystal violet, ethyl eosine, mercury sultide and zinc oxide, etc.
  • carrier liquid for instance, phthalocyanine blue, crystal violet, ethyl eosine, mercury sultide and zinc oxide, etc.
  • cyanine green and powdered sulfur or selenium, etc. are liable to be charged negatively.
  • the coating of the surface of suspended particles with insulating resin is being widely applied.
  • ethyl cellulose, polyacryl ester resin, linseed oil modified alkyd resin and polyvinyl acetate resin, etc. are used as a charge control agent for positive charging and polyvinyl chloride resin, chlorinated polypropylene resin and polyvinylidene chloride, etc., for negative charging.
  • the present invention relates to a liquid developer containing toners with negative charges.
  • Developers containing toners with negative charges are described in many patent specifications but are not so satisfactory.
  • Time-instability of the negative toner in carrier liquid is reported, for instance, on Page 370 of Electrophotography" written by RM. Shaffert (published by Focal Press Co., 1965).
  • a liquid developer to be employed in a developing equipment it is necessary that its dispersed state stably remains uncharged over a long period and that the toner charge sign as well as the quantity of charge is stable in course of the lapse of time.
  • the dispersed toner particles For the purpose of ensuring a sharp line copy or reproduction of continuous gradation, it is necessary for the dispersed toner particles to be uniform in size and small in grain size. It has been extremely difiicult to prepare a liquid developer containing toners with negative charge meeting these requirements.
  • the object of the present invention consists of providing a process of preparation of a novel liquid developer containing toners with negative charges.
  • Another object of the present invention is to provide a negative toner liquid developer possessing excellent time-stability.
  • One of the other objects of the present invention is to provide a method of manufacturing liquid developer containing fine toners uniform in grain size, with excellent dispersion of toners therein being one of the prominent features of the present invention.
  • Another important object is manufacturing of liquid developer suitable for achieving reproduction in continuous gradation and further in the provision of a preparation process of liquid developer suitable for color electrophotography. Providing a liquid developer possessing excellent preservability and especially suitable for use in automatic developing equipment is also one of the important objects of the present invention.
  • the liquid developer to be prepared according to the present invention includes toners with negative polarity, in the case of a sensitive layer such as selenium, which is used by positive charging, a positive image is obtained as the copy if the original is a positive image (ordinary development).
  • a sensitive layer comprising zinc oxide as photoconductive materials, for instance, Electrofax paper, etc., which is used by negative charging, a positive copy is obtained from a negative original (reversal development).
  • the liquid carrier employed under the present invention should preferably possess high insulating property and a low dielectric constant and concretely, the one with specific resistance of over 0. cm and specific dielectric constant of less than 3.5, serves the purpose.
  • Available as such substances are various aliphatic hydrocarbons, aromatic hydrocarbons, chlorinated hydrocarbons, chlorinated-fluorinated hydrocarbon and fluorinated hydrocarbon, etc. Desirable in view of practical behavior are heptane, hexane, kerosene, cyclohexane, gasoline and light oil, etc.
  • the surface of the coloring material employed is covered with charge control agent and does not directly touch the carrier liquid, for which reason the polarity of charge on the dispersed particles is determined only by the nature of the control agent employed regardless of the surface property of the individual coloring material.
  • various pigments can be applied as the coloring material, for instance, inorganic pigments such as carbon black, black iron oxide, nickel oxide, chrome oxide, cobalt ferrite, titanium oxide, zinc oxide, mercury iodide, mercury sulfide, lead oxide, cadmium sulfide, pulverized sulfur, various metallic powder and organic pigments such as phthalocyanine blue, alkali blue, hansa yellow, ponceaux 2R and naphthol yellow, etc. If dyestuff is employed as the coloring material, coloring matter can be obtained on another supporting medium by way of an appropriate mordanting process after development.
  • inorganic pigments such as carbon black, black iron oxide, nickel oxide, chrome oxide, cobalt ferrite, titanium oxide, zinc oxide, mercury iodide, mercury sulfide, lead oxide, cadmium sulfide, pulverized sulfur, various metallic powder and organic pigments such as phthalocyanine blue, alkali blue, hansa yellow, ponceaux 2
  • spirit blue for dye transfer using alcohol and acid violet 6, acid red 5, acid yellow 23 and acid blue 54, etc., for dye transfer by water are available.
  • Coloring materials can be applied without special restrictions under the present invention, provided that those materials are insoluble in the carrier liquid to be employed. lodine, oil yellow and spirit black, etc., are eliminated for this reason.
  • the polymer to control the charge of dispersed toner particles those which carry negative charges on the surface when brought into contact with the carrier liquid are employed.
  • available as such polymers are polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, chlorinated rubber, chlorinated polypropylene and nitrocellulose, etc., and various copolymers whose principal constituents are the monomers of these polymers, for instance, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-vinyl acetate copolymer, 'vinyl chloride -vinyl acetate-vinyl alcohol terpolymer, vinyl chloride-vinyl acetate-maleic acid terpolymer, vinyl chlorideacrylate copolymer, vinyl chloride-acrylonitrile copolymer and vinyl chloride-chlorotrifluoroethylene copolymer, etc.
  • carrier liquid soluble resins are used in a dissolved state in carrier liquid, the tolerable limits of electric resistance or dielectric constant of these resins are determined according to the amount to be added to the liquid carrier.
  • substance soluble in carrier liquid to be used jointly with charge control polymer various types of high-insulating, various kinds of vegetable oils which comprise glyclol ester of long chain fatty acids, are also applicable besides the above-mentioned various resins.
  • linseed oil, tung oil, soybean oil, peanut oil, sesame oil and so on can be employed. In this case too, if their compatibility with the charge control polymer were insufficient, they may be utilized by adding a small quantity of solvent for the charge control polymer. It is also possible to use these oils in combination with the aforesaid carrier liquid soluble resins.
  • the dispersion stabilizer to be added to a carrier liquid under the present invention will be described in detail.
  • such dispersion stabilizer is described in detail as the so-called fixer.
  • the dispersion stabilizer in the present invention does not differ from the ones described in said published patents. That is to say, any types of resin, oil and wax, etc., which dissolve in carrier liquid can be used.
  • many charge control polymers possess thermoplasticity and therefore these additives need not especially act as fixers and substantially the hitherto described additives as fixers may be said to act rather as dispersion stabilizers.
  • drying of a developed sheet material becomes quite easy by dipping the wet sheet after development into a nonpolar liquid having a high evaporation speed, whereby much of the canier liquid soluble resin is liable to be washed off by the nonpolar liquid of high volatility and accordingly, it cannot work as fixing agent. Accordingly, in case of carrying out such a process, they need not especially be the conventionally employed drying oil, etc., but liquid nondrying oil, etc., can also be employed. As these dispersion stabilizers are used in a dissolved condition in carrier liquid, it is desirable that they possess high electric resistance and low dielectric constant, but such property limitations are subject to considerable changes according to the volume of addition to carrier liquid.
  • the combinations of vinyl chloride-vinyl acetate-vinyl alcohol polymer with drying oil type alkyd resin, vinylchloride-vinyl chloride-vinyl acetatemaleic acid copolymer with thermoplastic acrylic resin of low molecular weight and vinyl chloride-vinyl acetate -vinyl alcohol terpolymer with rosin modified alkyd resin, etc. are applicable.
  • those which are soluble in carrier liquid can be selected from among alkyd resins and maleic acid resins, etc.
  • charge control agent and carrier liquid soluble substance either one type of material or more than two types of material mixed may be employed respectively.
  • auxiliary solvent in paste preparation is an effective means in that compatibility is improved and kneading is made easy.
  • the amount of such auxiliary solvent, especially when the solvent has a high polarity, should be minimized, since the solvent is introduced in the final liquid developer upon dissolution of the paste.
  • the amount leading to a satisfactory result is some 3 to 50 parts by weight with respect to l part by weight of the coloring material.
  • An example which led to a satisfactory result in the case of carbon black vinyl chloride copolymer nondrying oil type alkyd resin was 0.5 to 5 parts by weight of vinyl chloride copolymer and to 50 parts by weight of alkyd resin as against 1 part by weight of carbon black.
  • vinyl chloride copolymer is the carrierinsoluble component serving as charge control agent
  • nondrying oil type alkyd resin is the carrier-soluble component.
  • the amount of solvent to be added in case of insufficient compatibility between carrier-soluble substance and polymer is determined by the relative amount and properties of these two substances, it was sufficient to add nearly equivalent to charge control polymer or parts by Weight.
  • the amount of dispersion stabilizer (according to the conventional term, fixer) to be added to the carrier liquid is dependent on the volume of paste to be dispersed and dissolved in the carrier liquid, it is desirable, from a viewpoint of handling, to add 0.5 to parts by weight per 100 parts by weight of carrier liquid. In case the amount is too small, prepared liquid developer becomes unstable. In the case where the dispersion stabilizer has high resistance and low dielectric constant, such as linseed oil, applying a larger amount is quite acceptable. A developer containing such large volume of stabilizer has high viscosity and the dispersion of toners becomes excellent, but has a disadvantage the develop ing speed is reduced and accordingly it becomes necessary to employ a sensitive layer slow in dark decay of surface charge in the carrier liquid.
  • porcelain ball mill for the preparation of paste, porcelain ball mill, agitator, vertical ball mill, planetary type agate ball mill, colloid mill and at Arlington, etc., are suitable. Use of'chilled roll, etc., is also effective and suitable for the preparation of good paste. If, prior to the dispersion of prepared paste, a solvent was used for mixing polymer and resin, it is also desireable to volatize it to some extent and then proceed to the next step.
  • the paste thus obtained is then dissolved and dispersed in the carrier liquid containing a stabilizer (fixer), for which purpose, generally speaking, it is desirable to employ a high perfonnance agitator.
  • a stabilizer for which purpose, generally speaking, it is desirable to employ a high perfonnance agitator.
  • homogenizer and electric mixer are applicable and especially the use of ultrasonic disperser led to a satisfactory result.
  • the temperature at the time of dispersion it has been found that not too high temperature generally leads to the developing liquid in stable dispersion condition.
  • the liquid developer containing an insulating bonding medium such as wax in the developing liquid is described in the Japanese Pat. No. 40-9788, waxes are apt to be separated at low temperature according to the said description and affect the negative charge toners, for which reason the use thereof in the present invention is inappropriate.
  • the coloring material is covered with charge control polymer and surrounded by the adsorbed dispersion stabilizer.
  • charge control polymer is covered with charge control agent and thereafter dispersed, for which reason it involved the disadvantage that fine grains of toner were hard to obtain and the dispersion was liable to be unstable.
  • the cause is deemed to be attributable to the fact that kneading and crushing are carried out for many hours after the addition of charge control agent, for which reason impurities carrying opposite charges are liable to be introduced into the developing liquid and the surface of coloring material itself comes to touch the carrier liquid due to the peeling ofi or crushing of coat.
  • carrier-soluble substance flows out of the paste into the carrier liquid, the paste is decomposed and charge control polymer insoluble in the carrier liquid and containing the coloring material, is separated as the toner and dispersed.
  • the stabilizer in the carrier liquid and efiluent carrier-soluble substance (resin, oil) are adsorbed to the fine toner particles just separated and prevent the adhesion of toner particles, extremely stable developing liquid being thus obtained.
  • the coloring materials are completely covered with charge control agents, becoming uniform in the size, and therefore, all the toner particles come to carry nearly equal charges.
  • toner particle dispersion there may be included partly the effect that the material covering the coloring material in the case of dispersion acts as a wetting agent, making easy the adsorption of stabilizer (fixer) in the carrier liquid.
  • stabilizer fixer
  • the paste is prepared by kneading the coloring matter and resin or oil soluble in carrier liquid together with charge control polymer being dissolved with said resin or oil and insoluble in the carrier liquid, for which reason when such paste is added to canier liquid, carrier liquid soluble components contained in large quanti- EXAMPLE I
  • the following components were kneaded for 15 hours using a porcelain ball mill: 1
  • Carbon Black (Nipeal No. I00 made by Nittetsu Chemical Industry Co. Ltd.)
  • Vinyl chloride-vinyl acetate-vinyl alcohol terpolymer (Denka Vinyl No. 10006, made by Electric Chemical Industry Co. Ltd.) Drying oil type alkyd resin (Solid Bekkosol I8, 70% oil, made by Nihon Reichhold Chemical Industry Co. Ltd.) Acetone 30 g. 40 c.c.
  • Kerosene 50 c.c. Cyclohexane 5O c.c. Linseed Oil 2 c.c. Non-ionic wetting agent 0.01 g.
  • the aforesaid zinc oxide light sensitive paper was charged by means of 7000 V corona and thereafter exposed for 2 seconds through a line image negative original by means of 5,500-lux light source (Printer for Quick Copy made by Fuji Photo Film Co. Ltd. Next, this sensitive paper was dipped for seconds in the above-mentioned liquid developer, taken out and dried. As a result, a sharp, somewhat mild and black positive image involving little fog could be obtained. This image was heat-fixed by means of infrared lamp.
  • EXAMPLE 3 The same sensitive layer as in the case of Example I was charged and then exposed through a negative original with continuous gradation and developed employing a gauze type developing electrode with a potential of -1 50V placed 0.5mm apart from the sensitive paper and in the liquid developer under Example 2. As a result, a positive image of continuous gradation could be obtained.
  • Phthalocyanine blue I g (RS l/l6) Nitrocellulose/(Daicell Co. Ltd.) 1 g Drying oil type alkyd resin 50 g Acetone 20 c.c.
  • Example l Using the-above and according to the same process as in Example l, a liquid developer for blue image could be obtained.
  • the liquid developer prepared from this paste using the carrier liquid under Example 1 provides a yellow image.
  • the liquid developer prepared from this paste provided a mild black image.
  • Type ll Acid violet 7 4.5 g. Vinyl chloride-vinyl acetate copolymer 4 g. Drying oil type alkyd resin g. Acetone 20 c.c. Butyl acetate 80 c.c.
  • thermoplastic acrylic resin is the carrier liquid soluble component whereas vinyl chloridevinyl acetate maleic acid terpolymer is the insoluble component.
  • a process for the preparation of an electrophotographic liquid developer comprising kneading together (1) a coloring material in fine particle form, said coloring material being insoluble in a nonpolar carrier liquid, (2) a charge control agent consisting of a material selected from the group consisting of a vinyl chloride polymer or nitro-cellulose which is insoluble in said carrier liquid, and (3) a material selected from the group consisting of thermoplastic acrylic resin, drying oil type alkyd resin, nondrying oil type alkyd resin, epoxy ester, rosin modified alkyd resin, phenol-modified alkyd resin, styrenated alkyd resin, rosin modified phenol-formaldehyde resin, phenol-formaldehyde resin, epoxy ester of vegetable oil fatty acids, and glyclol ester of long chain fatty acids and mixtures thereof, and (4) a liquid selected from the group consisting of acetone, butyl acetate, methyl ethyl ketone, and ethyl
  • vinyl chloride polymer is a vinyl chloride-vinyl acetate-vinyl alcohol terpolymer.
  • said carrier liquid is selected from the group consisting of heptane, hexane, kerosene, cyclohexane, gasoline and light oil.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Liquid Developers In Electrophotography (AREA)
US699365A 1967-01-20 1968-01-22 Method of producing electrophotographic liquid developers having very fine coloring material Expired - Lifetime US3668126A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
FR1562934D FR1562934A (fr) 1967-01-20 1968-01-18 Révélateur liquide et procédé de fabrication
BE709625A BE709625A (fr) 1967-01-20 1968-01-19 Révélateur liquide et procédé de fabrication
US699365A US3668126A (en) 1967-01-20 1968-01-22 Method of producing electrophotographic liquid developers having very fine coloring material
GB3319/68A GB1218064A (en) 1967-01-20 1968-01-22 Electrophotographic developer composition

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP42003908A JPS5233497B1 (fr) 1967-01-20 1967-01-20
US699365A US3668126A (en) 1967-01-20 1968-01-22 Method of producing electrophotographic liquid developers having very fine coloring material

Publications (1)

Publication Number Publication Date
US3668126A true US3668126A (en) 1972-06-06

Family

ID=26337571

Family Applications (1)

Application Number Title Priority Date Filing Date
US699365A Expired - Lifetime US3668126A (en) 1967-01-20 1968-01-22 Method of producing electrophotographic liquid developers having very fine coloring material

Country Status (4)

Country Link
US (1) US3668126A (fr)
BE (1) BE709625A (fr)
FR (1) FR1562934A (fr)
GB (1) GB1218064A (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4363863A (en) * 1979-12-13 1982-12-14 Nashua Corporation Liquid negative developer compositions for electrostatic copying containing polymeric charge control agent
US4374918A (en) * 1981-09-16 1983-02-22 Nashua Corporation Thermally stable liquid negative developer
US4937166A (en) * 1985-10-30 1990-06-26 Xerox Corporation Polymer coated carrier particles for electrophotographic developers
US5002846A (en) * 1985-10-30 1991-03-26 Xerox Corporation Developer compositions with coated carrier particles
EP0617803A4 (fr) * 1991-12-19 1995-01-18 Olin Corp Revelateur electrophotographique liquide se nettoyant facilement.
US20070117037A1 (en) * 2003-10-26 2007-05-24 Tomer Spector Liquid developer manufacture process
CN100529725C (zh) * 2005-05-24 2009-08-19 南京大学 铁电晶体表面电畴结构无损检测静电微粒显示剂及其检测方法

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3001888A (en) * 1957-09-25 1961-09-26 Commw Of Australia Method of developing an electrostatic image
US3053688A (en) * 1959-04-13 1962-09-11 Rca Corp Electrostatic printing
US3076732A (en) * 1959-12-15 1963-02-05 Bell Telephone Labor Inc Uniform n-type silicon
US3105821A (en) * 1960-02-04 1963-10-01 Rca Corp Electrostatic printing
GB1001570A (en) * 1961-05-24 1965-08-18 Australia Res Lab Electrophotographic developers
US3293183A (en) * 1961-08-14 1966-12-20 Australia Res Lab Developer for electrostatic images
US3417019A (en) * 1962-12-27 1968-12-17 Eastman Kodak Co Xerographic development
US3419411A (en) * 1963-09-06 1968-12-31 Australia Res Lab Method for the transfer of developed electrostatic images using a lattice forming substance
US3438904A (en) * 1966-01-10 1969-04-15 Scm Corp Liquid toner

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3001888A (en) * 1957-09-25 1961-09-26 Commw Of Australia Method of developing an electrostatic image
US3053688A (en) * 1959-04-13 1962-09-11 Rca Corp Electrostatic printing
US3076732A (en) * 1959-12-15 1963-02-05 Bell Telephone Labor Inc Uniform n-type silicon
US3105821A (en) * 1960-02-04 1963-10-01 Rca Corp Electrostatic printing
GB1001570A (en) * 1961-05-24 1965-08-18 Australia Res Lab Electrophotographic developers
US3293183A (en) * 1961-08-14 1966-12-20 Australia Res Lab Developer for electrostatic images
US3417019A (en) * 1962-12-27 1968-12-17 Eastman Kodak Co Xerographic development
US3419411A (en) * 1963-09-06 1968-12-31 Australia Res Lab Method for the transfer of developed electrostatic images using a lattice forming substance
US3438904A (en) * 1966-01-10 1969-04-15 Scm Corp Liquid toner

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4363863A (en) * 1979-12-13 1982-12-14 Nashua Corporation Liquid negative developer compositions for electrostatic copying containing polymeric charge control agent
US4374918A (en) * 1981-09-16 1983-02-22 Nashua Corporation Thermally stable liquid negative developer
US4937166A (en) * 1985-10-30 1990-06-26 Xerox Corporation Polymer coated carrier particles for electrophotographic developers
US5002846A (en) * 1985-10-30 1991-03-26 Xerox Corporation Developer compositions with coated carrier particles
EP0617803A4 (fr) * 1991-12-19 1995-01-18 Olin Corp Revelateur electrophotographique liquide se nettoyant facilement.
US20070117037A1 (en) * 2003-10-26 2007-05-24 Tomer Spector Liquid developer manufacture process
CN100529725C (zh) * 2005-05-24 2009-08-19 南京大学 铁电晶体表面电畴结构无损检测静电微粒显示剂及其检测方法

Also Published As

Publication number Publication date
FR1562934A (fr) 1969-04-11
GB1218064A (en) 1971-01-06
BE709625A (fr) 1968-05-30

Similar Documents

Publication Publication Date Title
US2993787A (en) Electrostatic printing
US3212887A (en) Laterally disposed coterminously adjacent multicolor area containing graphic reproduction receptor and electrophotographic process of using same
US3668127A (en) Liquid developer for electrophotography
US3559570A (en) Method of preparing and using a gravure printing plate
US4199356A (en) Electrophotographic process, of transferring a magnetic toner to a copy member having at least 3×1013 ohm-cm resistance
US3337340A (en) Method for the reproduction of color
US3804620A (en) Method of producing planographic plates by photoelectrophoretic imaging
US3729419A (en) Liquid developer
US3915874A (en) Liquid developer for use in electrophotographic transfer process
US3841893A (en) Charge control agents for liquid developers
US3104169A (en) Production of printing blocks, resists, transparencies, prints and the like by electro-deposition
US3749670A (en) Electrostatic liquid developer containing dye coated carbon particles
US3850830A (en) Liquid developer containing extender body particles
US3244633A (en) Liquid developers for developing electrostatic images
US3376133A (en) Multicolor electrostatic printing
US3793234A (en) Liquid developer composition
US3773507A (en) Electrophotographic reversal development process employing a pre-toner
US3971659A (en) Color electrophotographic process using photoconductive particles in liquid developer
US3779748A (en) Method of protecting images
JPH08160675A (ja) 湿式トナーおよびその製造方法
US3558342A (en) Development process for permanently fixing an image on an electrophotographic copying material
US3403023A (en) Dye sensitization of zinc oxide photoconductors
US3682825A (en) Process for the production of electrophotographic liquid developer containing gelatin
US3345161A (en) Photoconductive material and process for its preparation
US3334047A (en) Liquid dispersible toner for electrophotography